Air pollution control strategies R for on-road mobile sources in Taiwan

The effectiveness of air pollution control programs for mobile sources in Taiwan during last ten years has been evaluated. Vehicle kilometer traveled (VKT) and registration numbers of on-road vehicles increase 60-70% during the past decade. Taiwan Environmental Protection Agency has developed a comprehensive strategy based on both incentive and command-control approaches to reduce emissions from on-road mobile sources. Several programs have been conducted; which include adoption of new exhaust emission standards, an enhanced inspection and maintenance program, a clean fuel program, a high-polluted vehicle retirement program, and a transportation management program. The results showed that enhanced emission standards for new vehicles are effective. The Smoke-check program for motorcycle and diesel engines has showed significant abatement potential for air pollutant emissions. The clean fuel programs including phase-out of leaded gasoline and sulfur content reduction in fuel are also effective. The incentive program for high-polluting vehicle retirement and promotion of cleaner vehicles has shown the slight abatement of air pollutant emissions. Overall, motorcycle control measures present significant abatement of NMHC and CO emissions. The emission reductions of CO, NMHC and NOx could be achieved by implementing gasoline vehicle control measures. Diesel engine measures are effective for particular matter emission abatement. However, more effective measures for in-use vehicles should be proposed for further emission reduction in Taiwan.